An LED is used as a light source of an illumination apparatus. This light source is constituted as a light-emitting apparatus in which bare chips of many LEDs are mounted on a substrate, the respective LED chips are electrically connected to each other through bonding wires, and the substrate is fixed to an attachment member by fixing components such as screws.
In recent years, in such a light-emitting apparatus, a high output has been demanded. To realize this high output, a current supplied to the LEDs must be increased. However, when the current to be supplied is increased, a temperature of the LEDs rises, and the LEDs are operated at a high temperature. In consequence, a temperature of the substrate is also increased, and hence a difference between thermal expansion and contraction of the substrate becomes large in a thermo-cycle of on/off of the LEDs.
In the above-described configuration, when the substrate is fixed to the attachment member with fixing components such as screws, stress is applied to the substrate because of a difference in heat characteristics such as a difference in thermal expansion coefficient between the substrate and the attachment member. As a result, the substrate may be deformed or cracked, whereby the substrate may be possibly damaged.